Oil casing plug



June 23, 1931.- u. G. SKELLY 1,311,407

oIL CASING PLUG Filed June 25. 1930 Patented June 23, 1931 PATENT OFFICE ULYSSES G. SKELLY, F LS ANGELES, CALIFORNIA OIL CASING PLUG Application filed June 25, 1930. Serial No. 463,689.

The invention formin of this application is a re extinguisher for oil well casings, and has for its object to rovide a very simple and highly eiiicient instrument for this purpose, a'nd one which can be very readily operated.

The invention includes mechanism for positioning the extinguisher vertically over the oil casing and for releasing the extinguisher l0 to allow it to fall by gravity when the axis of the extinguisher-1n the form of a tapered plug-is in alinement with the axis of the casing. i

Another object of the invention is to prol5 vide the extinguisher plug with means which not only locks the plug in its fire extinguishing position in the end of the casing, but

also embraces this end to prevent bursting thereof by thevimpact of the tapered end or part of the extinguisher plug.

Other objects of the invention will become apparent as the detailed description thereof proceeds.

In the drawings:

Figure 1 is a side elevation of the extinguisher-plug supported coaxially with and vertically over an oil well casing i and Figure 2 i's a side elevation of the plug itself in position in the end of the casing, 30 which is shown in this figure and in Figure 1 in vertical section.

In Figure 1 of the drawings, the extinguisher-plug is shown asa heavy spherical mass suspended vertically over the oil cas- 35 ing 1, and includes the spherical part 2 having a cylindrical extension 3 depending ytherefrom and terminating in a conical member 4, the extension 8 and member l having a common axis Apassing through the 0 center of the part 2. clamping annulus 5 its frictionally over the cylindrical extension 3, and sha ed to form a downward extension 6 which 1s bent inwardly and upwardly to form an annular fiange' 7 adapted 45 to engage the top 8 of the casing 1 when the extinguisher plug is in operative position on the said casing. The operative position of the extinguisher-plug is shown in Fig. 2 of the drawings. Particular atten- 59 tion is directed to the fact that, in this last the subject mattei'- named position, the bulged inner part 9 of the clamping annulus is in clamping contact with the outer wall o f the casing 1. This clamping annulus, however, is formed originally so that the annular part 9 thereof will just clear the outer cylindrical surface of the fcasing 1 and offer no resistance to the 'proper seating of the extinguisher-plug in the open end of said casing.

The spherical part 2 of the extinguisherplug is provided with a yoke 10 adapted to receive the jaws 11 and 12 of a pair of tongs mounted tovswing freely about a pivot 13 and having a pair of arms 14 and 15 disposed on opposite sides of the said-pivot, the said pivot 13 being suitably supported by a member 16 from the hook 17 .of a derrick used to locate the extinguisher-plug vertically over the casing 1. The hook 17 is supported by any suitable means, such as the 7 cable 18 which forms part ofthe derrick equipment, not otherwise shown herein.

The upper` part of the arm is provided with a pivot 20 about which is swung the clevis 21, having a cable 22 attached to its free end to swing it from the operative position, shown in full lines in Fig. 1, to the dotted line position shown in the same figure. The clevis is formed with a slot 23 having a curved outer end wall 24 adapted to slide freely over the curved end 25 of the arm 14 whenever the cable 22 is pulled upwardly. It will be noted that the lower inner edges of the jaws 11 and 12 are shaped so that the weight of the extinguisher-plug will cause the jaws to spring apart whenever the clevis 21 is moved from its operative to its inoperative position. It will also be noted that this clevis when raised to its inoperative position, clears the upper end of the arm 14 and permits the armsand jaws of the weight supporting tongs to swing apart and allow the extinguisher-plug to drop.

It is immaterial what mechanism is used to carrythe extinguisher-plug to the casing and locate it properly over the casing so that, when released, the plug will fall by gravity into the open end of the casing and smother any fire which may be raging therethe shank l26 extending in. It is also immaterial whether the plug 7be spherical or cylindrical in its outer end part. It is essential that the plug be heavy enoughto overcome the upward pressure of the gases emerging from theI casing, that its lower end be tapered so as to offer the mm1- mum of Vresistance to the emerging gases,l

and that its intermediate part be cylindrical and of slightly greater diameter than the internal diameter of the casing.

It is preferable to make the several parts of the extinguisher-plug separable from each pther, so that they can be readily assembled and disassembled. Accordingly, the spheri- .cal part 2 is diametrically bored to receive from the yoke 10 and screwthreaded at' 1ts free endto be screwed into a corresponding screwthreaded bore 27 formed axially in the cylindrical ex- I 2otension 3 of the plug.

The upper end of the extension 3 is slightly reduced to form a shoulder 28 which.v serves as a means for detachably clamping` the annulus or sleeveL 5 in. proper positionv against the spherical' part 2, when the parts thereof are assembled as shown in the drawings. Preferably, too, the rough tool marks Y of the lathe are allowed to remain on the extension 3 in orderA to increase the frictional grip between the plug and .the casin when the, plug is positioned, thereon.

n the operation of the invention, the plu is positioned vertically over the open en of the casing, with the axes of the plug and .casing as nearlyas possible coincident. The clevis 21 is then pulled to inoperativeu v dotted-line-position, and the weight of the plug`causes it to fall into the' openend of the casing toA close said end and smother the fire in the1 casing.r In the closing position, the sleeve 5 embraces the end of the casing i' and prevents the splitting'thereof, andi also the plu serves as anl additlonal means for holding in itsire-extin ishng osition. When t e fire is extinguis ed, the p ug may be removed very readlly vby unscrewing the bolt 26 and removing the spherical part 2 Aandthe sleeve 5 and then screwing the bolt again into the extension 3 to effect removal thereofby connecting the yoke 10 to the hook 17 ofthe derric It is immaterial just what'p'articular type -of lderrick is used to Aposition the extinguls er-plug over 'the openv end vof the-well casing 1. It will be obvious that any kind ofv v atruck; either on a track or onwheels indey u pendent of atrack, :may have its front end provided with some kindvof apositioning notch Aso that when the notch engages theA casin '1. wilbe properly located tosdrop the exl tmguisheri plug into the open end of the 'f'fnotch ,adapted to engage the slde of the 1, and ma have the derrick mech-vv amsm'located re ative to this positioning the ,tong mechanism shown 1n Fig.

-tobea casing. The tongs mechanism forms/an essential (part of my invention; but the derrick an truck mechanism ma be supplied very readily by anyperson s illed in this vWhileI haveshown and described a specific form of extinguisher-,plug and operatf ing mechanism therefor, it must be understoodthat my invention is not to be considered as limited to the form shown,l-'-nor in any other manner, except as expressly limited by the scope of the claims appended thereto.

1. A fire extinguisher-plug for gas and oil adapted to lit tightly the inner eriphery of the casing to which it is inten ed to be a plied, a tapered extension on one end of said body, and a sleeve secured to the other end `of said body' and adapted to fit the outer periphery of said casing when the body is seated therein.

2. A lire extinguisher-plug for as and oil well casings` com rising: a cylin rical bodyadapted to fit tig tly the inner periphery of the casin to which it is intended to be applied, ang a sleeve detachably secured to said well casings comprising: a lcylindrical body A ody .and adapted to fit tightly around thel outer periphery of said casing when the saidbody 1s seated therein.

3. A fire extinguisher-plug for as and oil well casings comprising: a cylin rical body adapted to lit tightly within the inner eriphery of the casing to which it is inten ed to be a plied, a conical extension on one end of said) bod a wei ht of larger diameter than that o said bo y, a sleeveadapted to t tightly around the' outer peri hery of said casing, and means for detacgabl secuin said weight and sleeve to said gody.

adapted to lit tightly withinv the inner eriphery of the casing to which it is inten ed of sai v y, a weight, a sleeve adapted to fit tightlyaround the outer periphery of said casing, and means exten ing throu h said weight and sleeve tolsecure said weig t and slve detachabl to said body.

l5. A fire extinguis er-plug for as and oil well casings comprising: a cylin rical body adapted' to lit tightly within the inner vriphery of the casing to which it is inten ed .to be applied, a tapered extension on one fire extinguisher-plug or as and oil l well casings comprising: a cylin rical body,

tra

plied, a conical extension on Aone end mime? adapted fao l; lightly Within lie inner periphery of the casing to which it is designed to be eglied, e conical extension on one end of sai ody, e sleeve on the other end el seid body and adapted to t tightly allround the outer periphery of seid casing, and means for detachebly connecting seid sleeve to said body, seid extension sleeve and body having e common exis.

7. The combineeion with the cylindrical casing of en oil or ges Well of an extinguisher-plug having e cylindrical body adapted to t tightly Within the inner periphery of said casing, and e sleeve detachebly connected to said body end adapted lo t tightly around the outer periphery of seid casing, Ineens for ositioning seid body and sleeve vertically a, ove the open end of said casing, end means for releasing said p0- sitioning ineens to cause the plug'to fall into and seal the open end of said casing with the Yseid sleeve embracing the outer peripher of seid open end. n

n testimony whereof, l lieve vslgned my neme to this specicetion.,

'ULYSSES Gr. SKELLY. 

